TWR-K60N512-KEIL Freescale Semiconductor, TWR-K60N512-KEIL Datasheet - Page 73

• Manufacturer Part Number: TWR-K60N512-KEIL
• Description: K60N512 Keil Tower Kit
• Manufacturer: Freescale Semiconductor
• Series: Kinetisr
• Type: MCUr

Specifications of TWR-K60N512-KEIL

• Rohs Compliant: YES
• Contents: 4 Boards, Documentation, DVD
• Peak Reflow Compatible (260 C): Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: Freescale Tower System, K60N512

Figure 7-4
source request, and the transfer activation.
The hardware provides ten “ always enabled request ” sources that can be used in
periodic trigger mode. These permit transfers to be initiated based only on the PIT. This
is shown in
7.2.3 Multiple transfer requests
Only one channel can actively perform a transfer. To manage multiple pending transfer
requests, the eDMA controller offers channel prioritization. Fixed priority or round robin
priority can be selected.
In the fixed priority scheme each channel is assigned a priority level. When multiple
requests are pending, the channel with the highest priority level performs its transfer first.
By default, fixed priority arbitration is implemented with each channel being assigned a
priority level equal to its channel number. Higher priority channels can preempt lower
priority channels. Preemption occurs when a channel is performing a transfer while a
Freescale Semiconductor
trigger are active. This provides a means to gate or throttle transfer requests using the
PIT. This is normally used for periodically polling the peripheral source status to
control the transfer schedule or for periodical transferring.
shows the relationship between the PIT periodic trigger, peripheral transfer
Figure
7-5.
Kinetis Quick Reference User Guide, Rev. 0, 11/2010
Figure 7-4. PIT gated transfer activation
Figure 7-5. PIT-only transfer activation
Chapter 7 Enhanced Direct Memory Access (eDMA) Controller
73